Draw press for sheet metal



Nov. 17, 1925. 1,561,770

G. W. BERRY DRAW PRESS FOR SHEET METAL Filed Feb. 21, 1924 2 Sheets-Sheet 1 INVENTOR.

qeorg a William Bern.

ATTORNEY, W

Nov. 17,1925- G. w. BERRY DRAW PRESS FOR SHEET METAL Filed Feb. 21, 1924 2 Sheets-Sheet 2 auge William Berry ATTORNEY.

Patented Nov. 17, 1925.

UNlTED STATES 1,561,770 PATENT OFFICE.

GEORGE WILLIAM BERRY, OF WAKEFIELD, ENGLAND, ASSIGNOR OF ONE-HALF TO CHARLES JOSEPH RHODES, OF VIAKEFIELD, ENGL AND.

DRAW PRESS FOR. SHEET METAL.

Application filed February 21, 1924. Serial No. 694,221.

To uZZ whom it may concern:

Be it known that I, GEORGE rauma: Bunny, a British subject, residing at \Vakefield, in the county of: York, England, have invented certain new and useful Improvements in Draw Presses for Sheet Metal, of which the following is a specification;

This invention relates to draw presses for sheet metal and particularly to those which are known as combination presses, that tosay, in which the lower die is provided with a movable pressure ring usually connected by pins passing through the bed of the press and operatively connected to a Lit resilient butter composed for example of; rubber and which receives the pressure or erted by the upper die during the drawing operation.

Ithas been proposed in presses of the type mentioned to provide means whereby a predetermined pressure is constantly maintained on the pressure ring and also on the butter at all stages of the drawing operation irrespective of the length or depth of draw the latter function being in order that the resilient properties of the buffer may not be impaired.

The present invention comprises improved means for the purpose or dual purposes above stated and these means embody a cam oscillated from a rotating part of the press and operatively connected to the pressure ring. This connection may be eiiected directly or through the medium of a resilient butter associated with the pressure ring, the

oscillation of the cam being suitably effected by means of rack and pinion mechanism actuated from the main driving shaft of the press. a

The invention also embodies the use of two pressure rings, with it required associated resilient bufiers one tor each of same, and operated by separate cams, such arrangement being for extra deep draws, one part of the draw being performed between the in ner and outer pressure rings and the other part between the outer pressure ring and the die.

The invention also comprises details of construction arrangement and combinations ot parts all as pointed out in appended claims and hereinafter fully descril'ied.

In the accompanying drawings.

Fig. l is a sectional front elevation of a press having the present improvements applied thereto, upper parts of the press be ing broken away. Fig. 2 is a side elevation from the lefthand of Fig. 1 and Fig. 3 is a side elevation, partly in section, showing an embodiment oi the invention and a modified arrangement of the die mechanism and its actuating means, which may be the preferred form of the invention, to effect a drawing of a blank in successive stages in a single movement of the reciprocatory die.

In Figs. 1 and 2 a designates the press bed and b the side frames thereof between which are mounted the reciprocatory ram or carrier for the upper die a with its usual or conventional spring plunger 0 and the lower die (Z having thepressure element or ring (Z connected by pins cl to a platform (Z which bears upon the buffer e. Now in this embodiment there is provided a rack and pinion mechanism f f respectively operated by means of a crank disc f or equivalent mounted on the main driving or crank shaft 9 of the press and coupled to the rack f as by means of a connecting rod The said rack is slidable in guides f on one side of the press bed 8 and gears with the idle pinion f which in turn meshes with another pinion i which is mounted on a cross shaft 2' in the bed of the press and which also carries a cam j so that as the crank disc 7 is rotated the cam is caused to oscillate by means of the rack and pinion mechanism f said cam in turn acting on a bell crank 7' which controls a supporting member 9' for the bufl'er c. This supporting member is guided on a stem 71: attached as by screwing at k to the base of the lower die (Z and is carried by means of a yoke to Z or similar element pivoted in links Z or thelike in such a manner that the support j may move in a vertical path. The said support is screw threaded for reception of a nut Z which bears on the yoke Z by adjustment of which nut the pressure of the buffer may be predetermined and varied as desired. Other convenient means for the same purpose may however be adopted.

The rack and pinion mechanism f, f is so adjusted that when the upper die 0 engages the drawing pressure ring al associated with the lower died in a drawing operation theta-ll in the cam is in contact with a roller other antitriction device on the hell 7' before mentioned, whereby the is allowed to descend with the ring crank al at the same speed as said upper die 0 due to the contour of the cam and cause a perfectly uniform pressure to be maintained on the pressure ring d and also on the buffer 6 throughout-the length of the draw.

In the embodiment illustrated in Fig. 3 the press bed and frame, rack and pinion mechanism'and crank disc with connections are not shown but are the same as described with reference to Figs. 1 and 2.

This embodiment particularly'for use when it is desired to'makeextra long draws and means are provided whereby the drawing operation may be performed in two stages in one drawing movement of the reciprocatory upper die' for which purpose two butfers m m and corresponding pressure rings 71 n are provided with their respective controlling earns a 50 mounted on cross shaft 2' The pressure rings n n are arranged concentrically'one withinthe other and of the stationary die and each acts through pins 0 o respectively on a plate 01' frame p 72 against which the respective buffers bear, the buffer supports 9' working one within the other and the support for the inner buffer passing through the outer buffer and the plate or frame 79 of the outer pressure ring m The outer support 9 is oper ated by links 9 (one shown) and yoke 93 through a bell crank acted on by cam 02 and the inner support Q is operated by links 1' (one shown) and yoke 1' through double armed lever 1 acted on by cam a2.

With such arrangeinent one part of the draw is performed between the inner pressure ring a and the outer pressure ring'n the said'inner ring being preferably curved or inclined at its upper edge 11 to avoid too sharp'angles in the metal under treatment, and another part of the 'Cll'tt\V is performed between the inner'pressure ring a and the inner face of thedie' e. Other arrangements may however be made so long as the pressure rings are acted on. successivelyby the upper die'and transmit their movements in similar sequence to the respective buffers each of which is controlled by an individual cam which ensures uniform pressure being maintained throughout the draw. The cams may be mounted coaxially as's'ho wn in Fig.

3 and be relatively adjustable as by means of slotand bolt connections t t to determine and vary the point at which tlie'iii-st draw terminates and the second draw coin mences. i y

In the arrangement of Figure 3'tlie' reciprocatory die 0 Illa-S a bore of .two diameters 3 and 4: with a plunger 0 slidably engaging in the portion of least diameter and'cai'ried by a rod 6 which is slidably mounted axially of the die and norii'iallyurged outwardly to a predetermined position by a spring 7 coiled about the' rod within the die, the outward movement of the plunger being limited by ahi'ut 8 0n the plungerrodabutting at the oute side of the die. In the operation of drawing the upper die 0 is reciprocated toward and away from the fixed die cl by the "press ram by a cancer crank on the shaft g.

a shallow cup which engages in the portion of the upper die of larger diameter 3. ing the continued descending movement of the upper die the partially drawn blank is gripped between the shoulder formed by the bore of the die of reduced diameter and the upper face of the drawing element or ring a when the blank is drawn to a reduced diameter and extended length over the central plug of the fixed die. As the upper die is moved upward the rings n, 97, participate in said movement through the action of the cams 00, 00 ejectingjtlie drawn shell from th fixed die and as theshell has a tendency to expand it causes it to be retained in the upper die, but as the upper die is cleared of the lower die the plunger 0 through the influence of the spring 7' will eject the drawn shell tlierefronu'or if desired means may be provided, such as a pivoted lever (not shown), to'act upon the end of the plunger carrying rod 6' to eject the drawn shell from the upper die.

hat I claim as my invention and desire to secure by Letters Patent of the United States is:

1. In a draw press for sheet metal, cooperating movable and stationary dies, a pressure ring embodied in and movable relative to one of said dies, rack and pinion mechanism operative from a moving part of the'press, a 'cam having a fixed axis actuated from said rack and pinion mechanism. and operative connections between said'cain and pressure ring operative through the movement of the C21111t0 control the movement of said pressure ring and maintain the same under a uniforn'i pressure during the drawing operation.

2. In a draw press for sheet metal. cooperating reciprocatory and stationary dies. at pressure ring embodied in and movable relative to one of said dies, a reciprocatory support including a resilient bu'fier fOi Silld pressure ring, rackand pinion mechanism operated from a moving part of the press an oscillatory cam operative through the movement of said rack and pinion and op ltl erative connections between said cam and pressure ring support whereby said cam is operative to control the movement of the support for the pressure ring and maintain the builer under uniform pressure during the entire drawing operation.

In a draw press for sheet metal, cooperating reciprocatory and stationary dies a plurality of concentric elements embodied in one of said dies adapted to be moved relative to the central portion said die and each other through the movement of the reciprocatory die, a shaft, a cam for each of said elements on said shaft adapted to be actuated from a moving part of the press in unison wit-h the movement of the recipro catory die, and operative connections between said cams and elements to control the movement of said elements in predetermined successive sequence relative to the movement of the reciprocatory die during the drawing operation whereby said elements successively act as die and drawing elements.

l. In a draw press for sheet metal, cooperating reciproeatory and stationary dies, a plurality of rings embodied in one of said dies and disposed one within the other, a reciprocatory support including a resilient buffer for each of said rings, said rings being adapted to be moved by and participate in the movement of the reciproeatory die a cam for each of said ring supports pivotally supported to have movement on an axis transverse to the direction of movement of the die mechanism and adapted to be oscillated in unison from a moving part of the press, and operative connectionsbetween said cams and ring supports to control the movement of the respective rings in predetermined successive sequence and maintain the same under uniform pressure during the entire drawing operation.

5. In a draw press for sheet metal, cooperating reciprocatory and stationary dies, a plurality of pressure rings embodied in one of said dies and disposed one within the other to have movement relative to said die and each other through the movement of the reciprocatory die, rack and pinion mechanism operated from a moving partof the press a cam for each pressure ring adapted to be oscillated in unison with the movement of the reciprocatory die through the actuation of said rack and pinion mechanism, and operative connections between said cams and pressure rings'to control the movement of the latter by the movement of the reciprocatory die in predetermined successive sequence and maintain the same under uni-V form pressure during the entire drawing op eration.

6. In a draw press for sheet metal, cooperatingreciprocatory and stationary dies, a pressure ring embodied in one of said dies, a pivotally supported cam adapted to be oscillated from a rotating part of the press, operative connections between said cam and pressure ringto maintain said ring under predetermined uniform pressure during the entire drawing operation, and means for adjusting said connections to vary the pressure on said pressure ring.

7. In a draw press for sheet metal, cooperating reciprocatory and stationary dies, a pressure ring embodied in one of said dies, a slidably mounted support including a resilient buiier for said pressure ring, a pivotally mounted cam, means to connect said cam with a rotating part of the press operative to oscillate said cam in unison with the moven'ient oi the reciproeatory die, operative connections between said cam and ring supportto control the movement of the ring and maintain the same under a uniform pressure do 'ing the drawing operation, and means for adjusting said operative connections to determine and vary the pressure on said butter and pressure ring.

8i In a draw press for sheet metal, cooperating reciproeatory and stationary dies, a plurality of pressure rings embodied in one off said dies, and disposed one within the other to have independent movement relative to said die and each other a cam for each oi said pressure rings, means to connect and oscillate said cams from a moving part of the press, connections between said cams and pressure rings operative to maintain the rings under a uniform pres sure by the movement of the cams during the entire drawing operation, and means for adjusting said cams to vary the relative period of operation of said pressure rings.

9. In a draw press for sheet metal, cooperating, reciprocatory and stationary dies, a plurality of pressure rings embodied in one of said dies and disposed one within the other to have independent movement relative to said die and each other, rack and pinion mechanism operated by a moving part of the press, cams for said pressure rings adapted to be oscillated through the actuation of said rack and pinion mechanism, connections between said cams and pressure rings operative to control the movement of said rings in succession and maintain the same under uni-form pressure during the entire drawing operation, and means for adjusting said cams to control the relative period of commencement of movement of said pressure rings.

10. In a press for drawing sheet metal hollow ware, the combination of a stationary die, a movable drawing member embodied in said die, a cam, connections between said cam and drawing member, rack and pinion mechanism in operative connection with said cam and a positive connection between said rack and moving part of the press whereby thee-am is oscillated and uniform pressure maintained on the drawing member during the entire drawing operation.

11. In a draw press for sheet metal, the combination ()1 a die, a plurality of members embodied in and movable relative to said die and each other, a cam for each of said members movable on an axis transverse to the direction of movement of said members and operatively connected thereto, and means positively operated by a moving, part oi the press for oscillating said cams whereby the said members are adapted to have movement in succession to eilect a drawing operation in successive stages and uniform pressure is maintained on the work during the entire drawing operation.

12. Ina draw press for sheet metal, the combination of a stationary die, a plurality of drawing members embodied in said die and disposed one within the other, a plurality of cams, connections-between the cams and saidpressure members, rack and pinion mechanism in operative connection with said cams, and positive driving means from a moving part of the press whereby the cams are oscillatedand the. drawing members are movable in succession to eileet a drawing operation in successive stages while uniform pressure is maintained on the work during the entire drawing operation.

13. In a draw press for sheet metal, the combination oi a die, a plurality of mem bers arranged concentrically of and movable relative to said die and each other, a cam Y for each of said members movable on an axis transverse to the direction of movement of and operatively connected to said members, and means positively operated by a moving part of the press for oscillating said cams to control the movement of said members to eiiect a drawing ope ation in successive stages during a single stroke of the press.

14. In a draw press for sheet metal, the combination of a die, a plurality of members embodied in and movable relative to said die and each other, a cam for each member, operative connections between each cam and the respective members, means positively operated by a moving part of the press for oscillating said cams whereby the drawing members are movable in predetermined sequence to eiiect a drawing operation in successive stages in a single stroke of the press, and means for adjusting the aforesaid operative connections to vary the pressure on said drawing members.

15. In drawing sheet metal, a fixed die and a plurality oi elements arranged concentrically. of and independently movable relative to the die and each other, a die reciprocatory toward and away from said fixed die, means to reciprocate said die, and means operative by the die reciprocating means to control the movement oi and place the movable elements under a constraining force having a constant value, and said reciprocatory die successively co-operating with said movable elements and the fixed die to eiiect a drawing of. the metal in successive stages in a single movement oi the reciprocatory die.

16. In drawing sheet metal, a fixed die and a plurality of elements movable relative thereto, a diereciprocatory toward and away from said elements and the fixed die, means to reciprocate the reciprocatory die, pressure buffers to exert a yielding force up on said movable elements in a direction to ward the reciprocatory die, and cams operative from the movement of the die reciproating means to maintain said pressure butler and movable elements under aforce having a predetermined-and constant value, and said reciprocatory die co-operating with said movable elements and the fixed die to efi'ect a drawing of the metal in successive stages in a single movement- 0f the reciprocatory die.

17. In a draw press for sheet metal, cooperating reciprocatory and stationary dies, and a plurality of elements arranged concentrically of one of said dies and movable relative to said die and'each other through the movement of the reciprocatory die, and with which elements the other die is adapted to successively co -operate to eiiect a drawing operation in successive stages by a single movement of the reeiprocatory die, and means for controlling the movement of and maintain said element under a force of constant value to resist the movementthereof by the reciprocatory die.

18. In a press for drawing sheet metal, a die embodying a central fixed plug and a plurality of elements arranged concentric of each other and said plug and movable relative to said plug and each other, reciprocatory supports for said elements, and cams oscillatory on an axis transverse to the direction of movement of said element and operated from a moving part of the press ei'igaging said supports and controlling the movement of the elements relative to the plug and each other.

19. In drawing sheet metal, a fixed die and a plurality of concentrically arranged and independently movable die and drawing elements movable relative thereto and each other, a die reciprocatory toward and away from the fixed die adapted to impart participating movement to the die and drawing elements, a shaft extending transverse of the die mechanism, cams on said shaft; and means operativeto oscillate said shaft and cams in unison with the movement of the reciprocatory die and co-operate with said vdie and drawing elements to place saidelements under a constant force to resist the movement thereof by the reclprocatory die,

and the reciprocatory die co-operating with the die and drawing elements and the fixed die to effect a drawing in successive stages in a single movement of the reciprocatory die.

90. In drawing sheet metalyco-operating reciprocatory and fixed dies, a plurality of concentrically arranged and combined die and drawing members associated with and movable independently relative to one of said dies and each other and adapted to have movement imparted thereto through the movement of the reciproca'tory die a cam for each of said die and drawing members pivotally supported to have movement on an axis transverse to the movement the die mechanism, and means operative from the movement of the reciprocatory die to move said cams to control the movement of said concentrically arranged die and drawing members in predetermined successive sequence relative to the movement of the reciprocatory die and exert a force on said members in a direction toward and to resist the movement thereof by the reciprocatory die.

21. In drawing sheet metal, co-operating reciprocatory and fixed dies, a plu 'ality of concentrically arranged and combined die and drawing members associated with and independently movable relative to one of said dies and each other and adapted to have movement imparted thereto by and participate in the movement of the reciprocatory die, and cams pivotally supported to have movement on an axis transversely to the movement of the die mechanism and co-opercling with the die and drawing members to control the movement thereof in predetermined successive sequence relative to the movement of the reciprocatory die and exert a pressure with a predetermined force on said members in a direction toward and resist the movement thereof by the reciprocatory die.

In drawing sheet metal, a die including a tin-ed element and a plu 'ality of con centrically arranged elements independently movable relative to the fixed element and each other, a die reoiprocatory toward and away from the first die and adapted to impart movement to the movable elements oi said first die, and cams pivotally supported to have movement on an axis transverse to the direction of movement ot the die mechanism and adapted to co-operate with the movable elements to control the movement thereof by the reciprocatory die in successive sequence and resist the lIlOVQlllGl'il? thereof by the reciprocatory die to efiect the drawing of a blank in successive stages in a single movement of the reciprocatory die.

23. In drawing sheet metal, a fixed blanking die, a second die arranged in concentric and spaced relation to the blanking die including a fixed element and a plurality oi: elements movable relative to the fixed element and each. other, a die reciprocatory toward and away from said dies and arranged to co-operate with the blanking die to cut a blank and with the movable elements of the one die to impart moven'ient thereto in. successive sequence, and cams pivotally supported to have movement on an axis transverse to the direction of movement ot the die mechanism to co-operate with the movable die ele ments to control and resist the movement thereof by the reciprocatory die to effect a cutting and drawing oi the cutting blank in successive stages in a single movement of the reciprocatory die.

Qet. In drawing sheet metal, a pair of dies one of which is tired and the other reciprocatory relative to the fixed die, one of said dies comprising a one piece block arranged with a bore having successive portions otrednced cross sectional area and the other die provided with auxiliary combined die and drawing members arranged about and movable independently relative to the die and each other to engage in the bore of the one die and adapted to be successively moved through the movement of the reciprocatory die by the engagement thereof with the shoulders formed by the reduced portions oi the die bore to e'itect a drawing in successive stages in a single movement of the reciprocatory die, and means to control the movement of and exert a pressure of a constant force on said auxiliary die and drawing members to resist the movement thereott' through the movement of the reciprocatory die during the entire drawing operation.

25. In drawing sheet metal, a reciprocatory die comprising a one piece block arranged with a bore havii'ig successive portions of reduced cross sectional area, a fixed die, a plurality of combined die and draw ing members arranged about and movable independently relative to the fixed die and each other and adapted to be moved through the movement of the reciprocatory die by the engagement thereof with the shoulders formed in the bore of the reciprocatory die by the portions of reduced area, and means operative from the movement of the reciprocatory die to control the movement of said die and drawing members and exert a pressure thereon having a constant force to resist the movement thereof by the reciprocatory die for the entire drawing operation.

In witness whereof I have signed th s specification.

GEORGE WILLIAM BERRY. 

